In-group variability and motivation to reduce subjective uncertainty.

Building on the subjective uncertainty reduction model of social identity processes (M. A. Hogg, in press-b; M. A. Hogg & B.-A. Mullin, 1999), it was hypothesized that homogeneous groups would be better than heterogeneous groups at reducing uncertainty and therefore that people would show more intergroup differentiation and turn more to a homogeneous in-group under conditions of uncertainty rather than certainty. Two minimal-group studies were conducted to investigate this idea. As predicted, when groups were homogeneous, more intergroup differentiation was observed under low certainty than under high certainty (Study 1). Study 2 provided evidence that group members turn actively to their group to reduce low certainty when the group is homogeneous. Low certainty led group members to request more feedback about other group members' responses, and they were more likely to change their initial responses when the in-group was perceived as homogeneous. These findings confirm predictions derived from the uncertainty model proposing that uncertainty reduction is a motivation for group behavior. These findings also highlight the importance of social structural factors such as perceived group variability in the uncertainty reduction process.